while evaluating wing ftp server i found one major problem for us, that maybe has to to with our proxy:We want to use the https-ftp server for file exchange in a separate net, that has access to the internet only via a central proxy.

The Problem: Each time i click on the Licence-Button of the admin-GUI, the server freezes for about one minute - no one is able to work with the server, neither admin nor any user.I could imagine it has to do with the update listener, who tries to connect to the wing-update-server and can't find the way until he get's a timeout.

So: ist it possible either to edit some proxy configs or to disable the update listener?

I am not very clear about your issue, but what I know is:When you click on "Server -> License", it will just receive a server version via ajax request, it will not freeze your server, even you have used proxy. If you don't believe it, just have a trial on our demo server, our demo server is running on Linux too.